Today, the petfood industry is using mainly the glucomannan or galactomannan-kappa carrageenan mixed systems in the production of products of type loaf, chunks in loaf and chunks in jelly. Typically, the jelly is made using semi refined carrageenan. The galactomannan family consists in guar gum, tara gum, carob gum (or locust bean gum) and cassia gum; the glucomannan consists in konjac mannan gum.
In production, the restructured meat chunks are mixed with a semi refined carrageenan liquid jelly (with other hydrocolloids and dry ingredients) and go together into the can. After retorting the semi refined carrageenan makes the jelly of final product.
Because these products are using semi refined kappa carrageenan the jelly is somehow “cloudy”. This cloudiness is due to the milder extraction procedure from algae which results in a carrageenan containing fragments of algal cell wall cellulose: of about 8-15% cellulosic material in the final composition of a typical semi refined carrageenan. In fact, the cellulose somehow precipitates during the retorting step and subsequently promotes the cloudiness of final gel. In reality, the meat just released from the chunks (containing some protein stuffs) may also complex with carrageenan cellulose precipitate, increasing even more the presence of precipitate material in the jelly.
The use of refined gelling agents, and particularly refined kappa carrageenan would improve the clearness of the final gel, but its use is quite limited in petfood industries due to high price, and semi refined material is largely used due to his low price.
Also, the chunk structure is achieved during the cooking and retorting steps mainly through animal or vegetable protein coagulation. Thus, the quality of the obtained chunks is highly dependant on the quality of the protein raw material. This is critical because of the variability of the supplier sources and because of the market crisis (e.g. BSE, GMO).
Therefore, the present invention aims to improve the chunk rigidity and the clearness, of gels and global product quality control in petfood products, without using refined gelling agents and/or functional proteins.